Fire extinguishing and fire protective method



Oct. 18, 1932.

B. RICHARDS FIRE EXTINGUISHING AND FIRE PROTECTIVE METHOD Filed Dec. 27, 1926 2 Sheets-511601: l

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wry uw. ubnuv Patented Oct. 18, 1932 Search heeft PATENT OFFICE BENJAMIN RICHARDS, OF KENILWORTH, ILLINOIS, ASSIGNOR TO EVERETT E. KENT, OF NEWTON, MASSACHUSETTS FIRE EXTINGUISHING AND FIRE PROTECTIVE METHOD Application filed December 27, 1926. Serial No. 157,020.

This invention relates to improvements in fire extinguishing and fire protective methods and to appartus for practicing the same. More particularly it relates to protection of inflammable liquids or other severe fire hazard. The invention pro-vides that when fire occurs or threatens, a buoyant earthy liquid producing a covering of essentially permanent character may be spread over a dangerous material or the inflammable contents of a tank or vat, preventing ignition, or smothering any combustion that may be in progress. In one form of the invention this floating liquid may become quickly solidified into a firm, refractory cover, resting on the surface of the combustible liquid.

The best methods hitherto known to me for combatting lires of this character have been through the use of either gas or foam.

2e Neither of these is of permanent character. The effectiveness of gas or foam quickly passes except as a fresh supply is continually played over the hazard; wind or heat may prevent them from reaching their destination; and they may be blown or washed off the surface they are sup-posed to protect. The bubbles of foam break rap-idly. If there is heat from a fire this drives off moisture and the bubble lm breaks the more quickly. Also, the materials for generating the gas or foam are subject to dilution and deterioration while kept ready waiting to be used; so that frequent attention and expense is involved in maintaining systems employing gas or foam. It is among my objects to avoid these characteristics of uncertain protection and expensive maintenance.

The present invention proposes the use of an aerated fluid body having characteristics of permanence, preferably a quick setting earthy cement, to be spread over the inflammable surface while the cement is in a nascent state and while the cement body is being lightened by the liberation throughout its mass of an incombustible gas which is being simultaneously generated therein by chemical action. This makes a fluid mass of bubbles which in a preferred form solidifies in a few minutes, with the setting of the ce- 53 ment, into a stiff, liglrt, floating, inc0mbustible cover. The material of this fluid or solid protective covering may be heavier than a liquid which is to be protected, but the bubbles which exist everywhere throughout it make it virtually so light that it floats on an inflammable liquid and can be spread over it until it has assumed the shape of the top of the tank or vat so as to cover the liquid fully; and then as the cement sets it becomes a cellular solid plate which cannot be blown off or washed off by hose or sprinkler action, but remains as a fixed fire proof covering. Ingredients can be chosen for making this quick-setting fluid-solid which are capable of being held ready mixed in dry form, at a convenient, close by, location., witho-ut danger of deteriorating or becoming diluted with lapse o-f time; and when needed can be mixed with water or other suitable liquid and spread, either automatically or by hand. In a preferred form the only step required is the addition of water to the prepared powdered materials, mixing and spreading over the surface which is t0 be protected. When the danger is past the solid cover can be broken up and removed without there having been injurious eects upon the material, over which it was spread. An example of the earthy material which can be used is gypsum partially calcined, an effective form of which is called plaster of Paris, mixed with a small proportion of chemicals whose reaction, when water is added, liberates carbonic acid gas simultaneously with the plaster reaction, so that the mass immediately swells to several times its former size, with formation of multitudinous cells containing this gas, and when set or solidified in this expanded form, has a virtual or apparent specific gravity such tha-t it will flo-at on an inflammable liquid. Material which may be used is already known for use in building construction where it is employed for insulation and filling of walls, being called cellular gypsum or aerated ypsum.

A method vof compounding this same is described under the title insulating substance in United States Letters Patent Reissue No. 15,952 of November 25, 1925, issued on application of Harold S. Ashenhurst. Howpresent invention are not limited to those there set forth, for other cement forming materials may be employed. The particular 5 kind of cement may be chosen with some regard for the kind of liquid or other substance which is to be protected, in order to avoid using a cement which may to an undue extent absorb the liquid vor react with the liquid or other substance which is to be protected. For most such cases gypsum is inert and is satisfactory. Unlike the practice in building construction it may be made to set more rapidly by the addition of a suitable amount of potassium sulphate or other crystallized salts; and for the generation of the gas which is to make the cellular structure it is not so necessary to avoid the presence of a soluble alkaline salt, as the high internal vapor tension in the cellular mass which such salts are believed to develop does no particular harm in the short time within which a fire extinguishing agent is used.

The present invention further contemplates the having of a supply of water and of the ready mixed powdered chemicals which are to form the cement and liberate the gas, with apparatus which is arranged to hold the water and chemicals apart in any suitable manner until needed and then to mix them and to discharge the mixture immediately upon the material which is to be protected, the mixture being thin enough so that it can spread over the surface of a liquid upon which it may be discharged.

It is intended that the patent shall cover by suitable expression in the appended claims whatever features of patentable novelty exist in the invention and devices disclosed.

In the accompanying drawings:

Figure 1 is an elevation, in medial section, of apparatus by which the invention may be practiced with water power for the mixing;

Figure 2 is a like view of apparatus which is entirely automatic with electric power mixer;

Figure 3 shows a portable device which can be attached to an ordinary hydrant for water and power, from which the extinguishing medium can be conducted through a hose to wherever wanted;

Figure 4 shows how the invention may be practiced in conjunction with a heat responsive automatic sprinkler head release;

Figure 5 illustrates apparatus by which the mixture may be forced under pressure through a distribution system to the location of a fire hazard; and

Figure 6 illustrates mixture and discharge on the injector principle.

It will be understood that the drawings are more or less diagrammatic.

In Figure 1, 10 indicates a hopper which may be of any suitable shape with a bottom discharge throat 10. It is shown hanging from a pipe 12 for supplying water under pressure from some unfailing source such as an automatic sprinkler system, and is over the tray or vat 14 of combustible liquid here representing any hazardous material which is to be protected from fire. Mounted within the container is a water power wheel 16 with vertical shaft 18 carrying at the bottoni a worm 20 nicely fitting the discharge throat and carrying above it mixing blades 22. Water from nozzle 12 can drive the wheel, but until then a dry powdered material 24 is held ready in container 10 by the'close fit of the worm 20 with the wall o f the throat 10. The material 24 may consist of partially calcined gypsum mixed with aerating material, such that when water is added reactions begin to hydrate the gypsum and simultaneously to liberate carbonic acid gas in bubbles in the midst of the water and of the gypsum product suspended therein, which is a sort of earthy cement in process of setting. When protection against fire is needed, a valve 26, controlling the water supply, is to be opened by hand or otherwise. Tater immediately enters the hopper 10 and drives the mixer 22 and worm 20. The water and powder are thus mixed, and become a fluid which is fed downward by gravity and by the worm 20, and which spreads over the surface of the liquid in the tank 14. The` mixture is too heavy and adhesive to be blown out of its path or from the liquid, and yet is light enough to float thereon. It soon sets lydraulically and thus becomes a rigid incombustible blanket which extinguishes the iiaming liquid if already ignited, or prevents fire reaching it if discharged before ignition has occurred. lVhen danger is past this solid blanket may be easily broken up and removed.

The apparatus of Figure 2 illustrates how the mixture can be applied automatically. The dry medium 24 is held by a hinged trap door4 28 in container 27 above a. mixer 22a and worm 20a. The valve 26a of water supply pipe 12a, is connected by linkage 3() with the door 28 so that valve and door open simultaneously when the weight W is allowed to fall. This is ordinarily held up by a suitable latch device 82 which is released by some suitable means such as a thermo responsive element 84 located where it will be affected by heat of burning liquid in tank 14a, or by dangerous heat reaching it from any other source. The opening of the valve 26"L and door 28, permits flow of water into the hopper 10a from a measured supply in tank 29, and iiow of the measured quantity of powder 24; and the movement of linkage 30 also results in the closing of switch 31 of an electric motor 33 for rotating the mixer 22ZL and worm 20a. The powder and water in hopper 10a are mixed and then discharged as previously described, by the feed worm 20a, flowing over the liquid in tank 14a and forming a floating protective covering therefor.

Figure 3 illustrates how Water may be taken from a hydrant 36, or other supply, and conveyed by a flexible conduit, such as a hose 38, to a portable mixing apparatus, 40, and there mixed with the powdered gypsum product. The dry medium is fed into hopper 42 from whence it enters the mixing chamber 44 where it is mixed with the water that comes through hose 38 and drives the water Wheel 16?) mixer 22?) and discharging worm 205. The mixture in fluid state is forced through the discharge hose 38 and nozzle, and may be directed upon any surface to be protected.

In Figure 4 I have shown apparatus wherein an automatic sprinkler head 46, by a releasing connection of the type disclosed in my Patent 1,761,406 of June 3, 1930, is employed to restrain the water in supply pipe 120, and the powdered product in the upper part of hopper 10c. A pair of trap doors 280 are held together by a strut 46a of the sprinkler head until the thermo-responsive element of the latter is fused. When this occurs the head opens permitting water to discharge into the hopper, and the strut falls, allowing the doors 280 to swing downward and the powder to fall into the lower part of the hopper. There it is mixed with the water by the wheel 160 and mixer 220, and the resulting fluid mixture is discharged by the outlet 20c.

In Figure 5 is illustrated a tank 14d containing liquid which is remote from the mixing apparatus but is connected therewith by supply pipes 48 leading to discharge nozzles 50 positioned within the tank above the level of its liquid contents. In this figure the solidified blanket P is shown floating in the liquid and completely protecting it from fire. In this case, the apparatus for mixing the powder and water is shown in the form of a hopper 10d containing the dry powder and a tank 52 for water. When the protective mixture is needed the water is fed into a mixing vat 54 through pipe 12d and the powder is allowed to fall from the hopper. The two can be mixed in the vat by hand or mechanical means, and the resulting mixture is then drawn off by a power pump 56 and forced through the pipes 48 to the discharge nozzles 50. In this application of the principles of the invention the water and powder supply may be considerably removed from the fire hazard of which there may be several supplied from the same mixing vat.

It will be understood that in each of these cases any suitable mixing device may be applied, the plain vanes illustrated being diagrammatical; that the power may be provided from some suitable source other than a head of the water which is to be used for mixture, as by electricity, or by al water motor whose spent water is discharged independently of the mixture, while only a measured quantity of water is applied to the mixture. Care should be taken that the mixing be not too violent in its action, and that the .'i

discharge of the mixture upon the fluid be not from too great a height. However, a fall of eighteen inches will ordinarily be safe, and the drop may be higher according to circumstances. virtual or apparent specific gravity of the cellular solid may be as low as .2; but inasmuch as it is not necessary for the resulting solid to contain any particular size of gas cells or to be itself of any particular predetermined thickness when spread upon the liquid (provided only that it is suiiiciently light to float and sufficiently' fiuid to spread easily) nor ordinarily to set within any precise time, the quantity of water relative to the quantity of solids in the mixture need not be precisely predetermined. The speed of setting of the plaster can be determined in advance as desired, either by the addition of a retarder as suggested in the said Letters Patent Reissue No. 15,952, or by the addition of crystalized salts in order to make a very quick-setting plaster, or by using as a base the plaster of Paris in pure form in which case it will normally harden and set in some five to fifteen minutes after being first mixed with water. In practice op-erative results have been obtained with the material known commercially as Insulex, and also the material known as Pyrocell may be used, both of which may be purchased in the market. The following is suggested as one example of a workable formula: Ten parts by volume of plast-er of Paris containing one-fifth of one per cent. of a suitable retarder such as glue, saw dust or tankage from packing houses; one part by volume of magnesium carbonate; and one part by volume of aluminum sulphate; all to be dry in powdered form and well mixed together; and held safely inert. "When needed for fire prevention, sufficient water is to be added to make a thick liquid, in which case plaster of Paris begins to be converted to gypsum and to set, and the other ingredients begin to react so as to release carbon dioxide. If a fibrous or powdered loading material or strengthening material of any sort b-e desired this may be added, in the prel'minary dry mixture.

Where no long hairs or fibres are present in the dry material the mixing and discharge may be by apparatus working on the ejector principle. Figure 6 typiiies this, wherein a bin 60 holding` the dry material has w`thin it an ejector tube 62 for water, having side inlet or suction branches 66 through which powder 64 is drawn into the pipe when water is flowing through it. The water-may be turned on by hand valve 65 or by automatic heat responsive valve in the supply line; and

By the process herein described the Ult L.

the mixing will occur as the powder moves on with the water through the discharge 68 and is spread with it over the surface to be protected. Before the actual delivery to destination there may be a mixing cup 69 set in the line of discharge.

. Vhile I haveJ particularly referred to this invention in its application for protecting inflammable liquids, its utility for fire protective purposes is not so limited. The aerated blanketing material employed in the practice of the invention is light in weight and thus may be used advantageously for'protecting fragile and flimsy solids such as celluloid and pyroxylin compounds. Aquantity of film, for example, may be protected without seriously injuring the film, inasmuch as the apparent specific gravity of the blanketing material may be as'low 'as .750 or lower. It has been described as being buoyant on inflammable liquids which have an apparent specific gravity ranging from about .780 to .970 or thereabouts.

When the bubbling fluid with its earthy cement in suspension is applied for extinguishing combustion of a liquid or solid body, the effect Vof the heat inmore rapidly driving off excess moisture hastens the setting of the cement to solid form'. Thus heat strengthens the extinguishing act-ion, instead of diminishing it as in the case of ordinary foam. However, the substantial weight of the fluid makes it more effective from the start than foam as heretofore used, whether it becomes solid quickly or slowly, or even -if ingredients are used which will never`become' solid. The water does not need'to be sup-l plied with measured precision as to quantity. The presence of an excess above the amount needed for chemical combination increases fluidity and makes the'mixing easier. But if the water be taken by emptying -a supply tank of predetermined measured capaclty, water can be taken in just the amount predetermined as being best for proper chemical combination with suitable excess Vfor pro viding fluidity, according to the measured quantity of powder which is prepared and ready for the particular fire protection desired. One way of doing this is suggested in Figure 2. This figure suggests the use of auxiliary power means such as an electric motor for accomplishing the mixing surely and rapidly, and without that greater flow 5f water which may happen where the water flow is used also for mixing power. It will be understood that any sort of power may be employed, and that except where automatic or power action is required the powder and water may be mixed and applied to the re by hand using only an ordinary bucket and stick. In case the invention is practiced by the use of a heavy fluid mixture which does not have the described quality of setting by chemical transformation to rigid form the materials Waiting to be used may be kept with the liquid and the powder ready mixed, or at least with the powder moist, leaving only the bubble producing element to be added at the time of release. In this case the degree of mixing needed at the moment of discharge is less, and less power is required for that purpose.

I claim as my invention:

l. The art of protecting combustible liquid from fire, which comprises the floating upon and the spreading over the surface, of the said liquid, of an autogenously-reacting fluid composition which during the said spreading contains a fluid vehicle, as water, which vehicle serves also as a reacting ingredient; and contains an earthy cementitious substance that rapidly reacts with and absorbs the vehicle and so is converted into inert and rigid solid form; and contains aerating ingredients, reacting with liberation and retention of gas throughout the applied fluid mass, in quantity sufficient to make the said fluid mass buoyant inthe said liquid; the said vehicle being held in said flotation on the liquid and held in films around bubbles of the gas, by its affinity for the cementitious material with which it is reacting. 2. The art of blanketing liquid comprising theapplying thereto of a liquid carrying in suspension an earthy substance and lled with bubbles interspersed in said earthy substance adapte'd'to solidify to rigid'solid form, and the said bubbles of gas being present in sufiicient'amount to make the whole buoyant on the liquid which is to be covered to be buoyant on the liquid which is to be protected.

3. The art of protecting a combustible liquid from fire 'comprising the applying theretoof a liquid carrying in suspension an earthy substance., which said carrying liquid has gas in the form of bubbles distributed through it in sufficient amount to make the whole be buoyant on the said liquid which is to be protected, is sufficiently fluid to distribute itself by flowing thereover, and is adapted by reaction and evaporation of the liquid which carried the earthy substance to solidify into a permanent solid and rigid cellular blanket covering the combustible liquid.

4'. The art of blanketing liquid comprising the applying thereto of a reacting bubble-generating, wall-solidifying liquid composition containing an earthy substance; the said reaction having the characteristic that it fills the fluid mass with bubbles so that the solidifying mass floats and expands to rigid form; and the said reaction having also the characteristic that the bubble walls solidify in their expanded condition, and the whole becomes a rigid, solid, aerated floating blanket, spread over the surface of the liquid.

Signed at Chicago, Illinois, this first day of September, 1926.

BENJAMIN RICHARDS.

d t Q CERTIFICATE OF CORRECTION.

Patent No. 1,882,911. October 18, 1932.

BENJAMIN RICHARDS.

It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows: Page 1, line 3, strike out the words "and to apparatus for practicing the same"; page 4, lines 101 and 102, claim 2, strike out the words "to be buoyant on the liquid which is to be protected"; and that the said Letters Patent should be read with these corrections therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this 29th day of November, A. D. 1932.

M. J. Moore, (Seal) Acting Commissioner of Patents.

(Seal) Patent No. 1, 882,911.

CERTIFICATE OF CORRECTION.

BENJAMIN RICHARDS.

It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows: Page 1, line 3, strike out the words "and to apparatus for practicing the same"; page 4, lines 101 and 102, claim 2, strike out the words "to be buoyant on vthe liquid which is to be protected"; and that the said Letters Patent should bel read with these corrections therein that the same may conform to the record of. the case in the Patent Office.

Signed and sealed this 29th day of November, A. 1932.

M. J. Moore, Acting Commissioner of Patents.

October 18, 1932. 

